<!DOCTYPE html>
<html lang="en"><head>
	<meta charset="UTF-8">
	<title>Document</title>
</head>
<body>

	<script>
		var a=[0,1,2,3,4,[5,6,7]];

		console.log(a);
		console.log(typeof(a));
		console.log(a.length);

		a.push(8);
		console.log(a);

		a[5].splice(2,0,5);
		console.log(a);


		a.splice(5,1,5);
		console.log(a);

		a[100]=100;
		console.log(a);
		console.log(a.indexOf(2));

        // console.log(a[-1]);

        var a=1;
    //表达式的值	2	  2     3     4     4 
        var b=(++a)+(a++)+(a++)+(a++)+(--a);
        //a的值	2	  3		4     5	    4
        console.log(a,b);

        var m=100;
        console.log(m>0&&m<99);        
        console.log(m>0||m<99);
        console.log(!(m>0||m<99));

        console.log(1&&4&&6);
        console.log(0||8||9)

	</script>
	
</body>
</html>